SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e57e835d529507caefdcd3316fee243f1a477d12366ca3899342a26557d022b' 
  AND token = 'hfJmQ1Rk4WueOPXZZ22EysV+EsNofiteyDZZHufE+Js=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}